FDA Clears First Blood Test to Help Diagnose Alzheimer's Disease

The US Food and Drug Administration (FDA) has given marketing clearance to a blood test that can aid in the early detection of Alzheimer's disease, the first of its kind to receive signoff in the United States. Developed by Fujirebio Diagnostics Inc., the test measures two proteins in blood plasma: pTau217 and beta-amyloid 1-42, which tend to correlate with the presence or absence of amyloid plaques in the brain, hallmarks of Alzheimer's disease. The test is intended for adults 55 and older showing signs and symptoms of Alzheimer's disease and can help increase access to detection and reduce reliance on expensive positron emission tomography (PET) scans.

Key Takeaways:

• The FDA has cleared the first blood test to help diagnose Alzheimer's disease, which measures two proteins in blood plasma: pTau217 and beta-amyloid 1-42.
• The test is intended for adults 55 and older showing signs and symptoms of Alzheimer's disease and can help increase access to detection and reduce reliance on expensive PET scans.
• The test has been shown to accurately detect the presence of amyloid plaques in the brain, with 91.7% of people with positive results having the presence of amyloid plaques confirmed by PET scan or cerebrospinal fluid test.
• The FDA reviewed clinical trial data involving plasma samples from 499 adults who were cognitively impaired, showing that the test had a high level of accuracy.
• The test does not measure amyloid directly but can signal its presence.
• The FDA has warned that the test is not a definitive diagnostic tool and must be assessed in conjunction with other clinical information from a patient.
• Preventive neurologist Dr. Richard Isaacson has been using the blood test for research and welcomes the FDA clearance, citing its simplicity and reasonable accuracy as a new era of Alzheimer's research.
• The FDA says the risks associated with the blood test are mainly the risk of a false positive or false negative test result.
• More research is needed to help inform how blood test results should be interpreted and used to make clinical decisions.

Statistics:

• 91.7% of adults with positive results using the blood test had the presence of amyloid plaques confirmed by PET scan or cerebrospinal fluid test.
• 97.3% of people with negative results using the blood test had a negative amyloid PET scan or cerebrospinal fluid test result.
• More than 2 in 5 people over the age of 55 in the United States (about 42%) will develop dementia in their later years.
• 10% of people aged 65 and older have Alzheimer's disease, and this number is expected to double by 2050.

Sources:

• CNN
• US Food and Drug Administration (FDA)
• Fujirebio Diagnostics Inc.
• Alzheimer's Association
• Alzheimer's Drug Discovery Foundation
• Institute for Neurodegenerative Diseases
• Penn Medicine